The health and beauty aids (HBA) industry has long depended on outdated delivery technology and cosmetic science. Many of the compounds and ingredients presently used have been in existence for hundreds of years. In particular, the formula for cold cream, developed in A.D. 200 by the Greek physician Galen, remained virtually unchanged throughout the early 1970's. In fact, it appeared that contemporary cosmetic science seemed to ignore new developments and discoveries in skin and hair biology. Although medical research was advancing at a rapid pace, particularly in the areas of aging, acne control and wound healing, until very recently, cosmetic manufacturers were reluctant to utilize the information derived from such research to produce novel cosmetic compositions.
No longer are HBA products simple concoctions of waxes and oils, extravagantly packaged and sold with even more extravagant marketing techniques. These products now contain active, effective ingredients developed through basic research and medical science and adapted for cosmetic chemistry. A host of new chemicals used in cosmetic products, such as the glycols and other alcohol derivatives, have become common additives in cosmetic products.
In the new cosmetics formulations, however, new additives sometimes become new skin irritants, merely replacing the old irritants. One of the primary reasons for adding these new additives is to produce a favorable effect in the product's characteristics, e.g. its feel, consistency, spreading effect, etc. These favorable characteristics, however, may be improved at the expense of skin irritation.
Little, if anything, has been done to develop a delivery vehicle for use in cosmetic products which can produce an end product which is truly hypoallergenic. By hypoallergenic, we mean that the product has a relatively small potential for invoking irritancy or an allergic reaction compared to current cosmetic or HBA products. The current wisdom is divided on what makes a product less irritating or hypoallergenic. According to a study conducted by the North American Contact Dermatitis Group (NACDG), fragrances were shown to cause approximately 50% of all known allergic reactions. In fact, numerous fragrances, especially including the complex esters are listed in the Hazardous Chemical Reference as being mild to strong irritants.
Removing the fragrances is one approach to solving the irritation problem. Even though all fragrances may be removed from a composition, the remaining ingredients may include allergenic and splotch-causing components. Very few of the manufacturers of hypoallergenic HBA or cosmetic products eliminate certain known skin irritants which the NACDG has found to be deleterious, for example, the preservatives, parabens and glycols. These substances are found in virtually every hair and skin care product on the market.
To complicate the problem of allergenic products, a number of other components which are quite often added to HBA products exhibit deleterious effects. For example, the inclusion of talcs, clays and phosphate-containing starches contribute to respiratory ailments in conjunction with dust mites. More seriously, talc has been implicated in a variety of human cancers, most notably, ovarian cancer. Dusting powders have been around for many years and may have escaped scrutiny as potentially harmful components. Recently, however, the American Pediatric Association has gone on record denouncing the use of dusting powders for use on infants because of the potential respiratory problems they can induce.
Nationwide opinion polls have reported that up to 50 percent of the population believes they have sensitive skin and have experienced adverse reactions to skin or hair care products.
Organosilicones are not found in nature and must be prepared synthetically. The ultimate starting material is sand (silicon dioxide) or other inorganic silicates, which make up 75% of the Earth's crust. The organosilicones were first synthesized in 1863 by Friedel and Crafts, who first prepared tetraethylsilane. In the following years, although many other derivatives were synthesized, it was not until the 1940's that widespread interest in organosilicon chemistry emerged.
Silicon is a relatively electropositive element that forms polar covalent bonds with carbon and other elements, including the halogens, nitrogen and oxygen. The strength and reactivity of silicon depend on the relative electronegativity of the element to which the silicone will be covalently bound. The polysilanes upon controlled hydrolysis readily form the polysiloxanes. These cyclic and linear polymers are commercially known as silicones. The cylic siloxanes are used in the present invention as delivery vehicles for body powders to provide compositions with unique characteristics.
The present invention has been developed to provide an alternative delivery system to traditional delivery systems, such system being both hypoallergenic and biologically compatible with the skin. It is also preferably ecologically friendly, i.e., substantially biodegradable or bioerodible.
In the case of anti-perspirant/deodorant formulations, under normal circumstances, it has been found very difficult to keep cyclomethicones within a stable solid or semi-solid suspension, especially when water and surfactants are not used. In prior art compositions, colloidal clays and fumed micro-ground silicone dioxide are used as thickeners and suspending agents for ingredients mixed with cyclomethicones. This approach has found some success in suspending fillers such as antiperpirant salts.
The prior art mixtures are primarily inorganic and have all the negatives of a topical skin irritant. Additionally, the products produce a noticeable white residue on the skin. The present invention addresses the problems found in these prior art compositions.